Authorities have issued severe traffic alerts in the South Bay after traffic collisions on Interstate 880 and Highway 101 closed lanes.

One lane on I-880 north in Fremont has reopened, while the investigation of a fatal crash on 101 has shut down the right lane in Menlo Park. No time was given for reopening the lanes.

The collisions took place almost simultaneously at about 5:30 a.m.

In Fremont, three to four cars collided on 880 near Auto Mall Parkway, causing injuries. The collision on southbound 101 at Marsh Road was a fatal crash at 1:25 a.m. that blocked the right lane and the ramps from Highway 84 to 101 south. Authorities did not identify the person killed.